Elemental Composition and Response to Nitrogen of Sunflower and Corn1
- R. G. Robinson2
The reason for the research was to learn the elemental composition of sunflower (Helianthus annuus L.) and to measure the crop's response to nitrogen and irrigation. Comparative performance of corn (Zea mays L.) and sunflower in yield, response to fertilizer, and removal of nutrients from the soil is of interest because sunflower is a new crop on many corn-growing farms.
The objective was to compare sunflower and corn in yield, elemental composition, response to nitrogen fertilizer, and removal of nutrients from the soil. The crops were grown on silt loam soil with and without nitrogen applied at various times and on sandy soil with and without nitrogen and irrigation.
Nitrogen at 75 or 150 kg/ha failed to significantly increase yield of either crop on fertile silt loam soils. On droughty sand, nitrogen at 224 kg/ha increased sunflower yield, but both irrigation and nitrogen were needed to significantly increase corn yield.
Treatments within a trial did not affect elemental composition except where treatment altered yield.
Sunflower achenes and vegetative parts had greater concentrations of most elements than did corn. However, the higher yield of corn offset this and resulted in greater soil depletion of most elements.
Concentrations are given of N, P, K, S, Ca, Mg, Na, Sr, Al, Fe, Zn, Cu, Mo, Mn, and B in corn and sunflower stems and leaves in prebloom stage and in mature sunflower achenes, sunflower stover, corn caryopses, and corn stover.
Sunflower yields were 35 to 40% those of corn under favorable soil fertility and moisture conditions. This research indicates that sunflower ranks below corn as a soil-depletive crop.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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